Jeffery, Thank you for your comments - some quoted below.
"The difference has to do with the scaling that was performed and the antialiasing done in Coastal Explorer to make their charts better."
>I tried to use the same scale for the Active Captain
(AC) and Cap'n. The second screen image published was done with only one file made available to the Cap'n.>
"PolarView's display is antialiased too but I think that screen shot was done at a scale closer to the original of the chart. A proper comparison should have all displayed scales identical."
<Polar View was not loaded on the computer used for the screen shots.>
"A couple of questions about the Cap'n version you're using:
- Does it quilt the charts together into a single
> No. Cap'n was run with a data set containing only a single file for the test. The version of Cap'n tested does not support quilting.?
"- Can you select any scale desired or does it only display the chart in multiples of the chart's native scale (1:40,000 chart would only be displayed as 1:20,000, 1:80,000, etc)?"
<Both CE and the Cap'n have tools that permit
arbitrary scales. CE uses a slide bar in the tool bar, Cap'n uses in and out zoom buttons. I tried to select the same sale
and tested to see if larger or smaller scales would improve the result.>
"- Can you make a screen shot of what the Cap'n chart shown previously looks like when it's rotated by 30 degrees?"
<No, I run North up.>
" In almost all cases, a quilted chart with antialiasing like Coastal Explorer and PolarView provide have much better results than the "nearest-neighbor" type of scaling done in the screen shot of the Cap'n shown in this thread."
<Maybe we should share an understanding of "Better". Better, to me, is the closest possible representation of the underlying paper Government
chart. Eliminating small canals or features is not better.">
I used my first copy around 1995. "
<I, also, began using Cap'n in the mid 90's. My current
, licensed, version is from about 1998. Unfortunately, it is no longer supported, even for a fee I'm willing to pay, and no longer supports tides.">
<While I have some understand of the difficulties involved in rendering the best possible image for the intended purpose in all conditions, I continue to believe the CE image of the areas I sail and have tested is inferior to the same image rendered by the much, much older Cap'n software
<This is about getting there and home safely. Clearly, no one can say that a more accurate chart image will prevent an accident
, but it might. The standard of excellence of an electronic chart rendering package is not really debatable, it should render a chart at least as well as a new, Government
issued, chart of the same area. My 20+ year old version of the Cap'n does this and the software I replace it with will also - not a very high bar to jump. >
Thank you, again, for your comments. Makes us all think clearer. /Stu